Draw structural (line-angle) formulas for: (a) 1-phenylcyclopropanol (b) styrene (c) m-bromophenol (d) 4-nitrobenzoic acid (e) isobutylbenzene (f) m-xylene.

Benzene and cyclohexene react differently with $\text{Br}_2$ due to their distinct electronic structures and stability.

• Benzene: Benzene is an aromatic compound, meaning it is cyclic, planar, fully conjugated, and follows Hückel's rule ($4n+2$ $\pi$ electrons, where $n=1$, so 6 $\pi$ electrons). This aromaticity confers exceptional stability due to extensive delocalization of its $\pi$ electrons through resonance. If benzene were to undergo addition with $\text{Br}_2$, the aromatic system would be destroyed, leading to a significant loss of resonance stabilization. Therefore, benzene prefers electrophilic aromatic substitution, where a hydrogen atom is replaced by a bromine atom, preserving the stable aromatic ring.

• Cyclohexene: Cyclohexene is a cyclic alkene and is not aromatic. It contains a localized carbon-carbon double bond. This double bond is electron-rich and readily reacts with electrophiles like $\text{Br}_2$ via an addition mechanism. The addition of $\text{Br}_2$ across the double bond forms a dibromocyclohexane product. There is no aromaticity to lose, so the addition reaction proceeds instantly as it is energetically favorable to break the $\pi$ bond and form two new $\sigma$ bonds.